1. Field of the Invention
This invention relates to an image transfer system, and more particularly to an image transfer system which transfers medical image data on a DICOM (Digital Imaging and Communication in Medicine) standard communication system.
2. Description of the Related Art
In the field of medical images, there has been a demand for a system which makes it feasible to transfer medical images between a plurality of systems and use the transferred images for diagnosis, for instance, a system which makes it feasible to store a CT image of company A and a MRI image of company B in an image server of company C and to reproduce for diagnosis the CT image or the MRI image on a CRT by a work station of company D connected to the image server through a network, or a system which makes it feasible to transfer a radiation image of company E to a work station of hospital F and display the result of diagnosis at the hospital F by a CRT of company G and output as a hard copy on film by a printer of company H. However, since the standard for handling medical image data from company to company, when transferring medical image data from a system of one company to a system of another company, the medical image data must be converted so as to conform to the system of the latter company, which deteriorates diagnostic efficiency.
Recently, the aforesaid DICOM standard has come to be used as a common standard for transferring medical image data. Since the DICOM standard supports TCP/IP protocol which is a current communication standard for Internet, by use of the DICOM standard, information on patients and/or medical image data can be transferred by way of a network between systems manufactured by different makers, whereby various drawbacks inherent to the conventional medical image handling system where medical images are recorded on photosensitive material and transferred in this state, e.g., that a large space is required to store medical images, fear of a loss of the film, that it takes a long time to transfer the film, and the like, can be overcome.
FIG. 5 shows a conventional medical image transfer system which transfers medical images on the DICOM standard. The medical image transfer system shown in FIG. 5 comprises an image server in which a plurality of medical images are stored and a plurality of terminals connected to the image server by way of a network. A request for a medical image (will be referred to as xe2x80x9cimage requestxe2x80x9d, hereinbelow) is sent to the image server from each terminal and the image server transfers to each terminal medical image data requested by the terminal. Conversely, it is possible to transfer medical image data created at each terminal to the image server and store the medical image data in the image server.
However in the communication between the terminals and the image server on the DICOM standard, since each terminal can send the image request to only one image server, when the requested image is not stored in the image server, the terminal must send the image request to another image server after it receives a message describing the condition and accordingly the efficiency in transfer of medical image data is low. Further even if the requested image is stored in the image server, the image transfer speed becomes low when access to the same image server is made by a plurality of terminals at one time.
As the protocol for transfer of a multimedia on Internet, there have been in wide use http protocol and ftp protocol and web browser which is software for displaying a multimedia by use of such a protocol has been wide used owing to its inexpensiveness. However software and hardware for displaying and transferring medical image data on the aforesaid DICOM standard communication system must support protocol for the DICOM standard and accordingly are very particular and very expensive. Further in order to carry out transfer of medical image data on the DICOM standard, an exclusive network is required and the construction cost of the network is high.
In view of the foregoing observations and description, the primary object of the present invention is to provide an image transfer system which can efficiently transfer medical image data.
Another object of the present invention is to provide an image transfer system which can efficiently transfer medical image data at low cost on a DICOM standard communication system.
In accordance with a first aspect of the present invention, there is provided an image transfer system comprising
one or more image servers which store medical image data, and
at least one terminal for instructing transfer of the medical image data from the image server to the terminal and/or transfer of the medical image data from the terminal to the image server on a DICOM standard communication system,
wherein the improvement comprises
a relay server which intervenes between the terminal and the image servers and makes access to one of the image servers on the basis of instruction from the terminal to execute transfer of the medical image data.
In this specification, the term xe2x80x9cmedical image dataxe2x80x9d should be broadly interpreted to sometimes include information on diagnosis of the patient and the like.
It is preferred that the image transfer system of the first aspect of the present invention be provided with a plurality of said relay servers.
Further it is preferred that the relay server be provided with a cache for accumulating therein a plurality of pieces of medical image data.
In accordance with a second aspect of the present invention, there is provided an image transfer system comprising
one or more image servers which store medical image data, and
at least one terminal for instructing transfer of the medical image data from the image server to the terminal and/or transfer of the medical image data from the terminal to the image server on a DICOM standard communication system,
wherein the improvement comprises
a relay server which intervenes between the terminal and the image servers, receives transfer of medical image data prior to instruction from the terminal, and is provided with a cache for accumulating therein a plurality of pieces of medical image data.
In this specification, the expression xe2x80x9cthe relay server receives transfer of medical image dataxe2x80x9d should be interpreted to include that an image server and/or a system for creating medical image data makes access to the relay server and transfers medical image data to the relay server as well as that the relay server spontaneously makes access to the image servers and receives transfer of medical image data. For example, the relay server may periodically access to the image servers and receive transfer of medical image data newly stored in the image servers, or the relay server may receive transfer of newly created medical image data when the newly created medical image data is transferred from the system for creating medical image data to the image servers by way of the relay server.
It is preferred also in the image transfer system of the first aspect of the present invention that the image transfer system be provided with a plurality of said relay servers.
In accordance with a third aspect of the present invention, there is provided an image transfer system comprising
one or more image servers which store medical image data, and
at least one terminal for instructing transfer of the medical image data from the image server to the terminal and/or transfer of the medical image data from the terminal to the image server on a DICOM standard communication system,
wherein the improvement comprises
a protocol conversion server which intervenes between the terminal and the image servers, transfers medical image data, transferred from the image servers, to the terminal after converting the DICOM standard protocol of the medical image data to a generalized protocol, and transfers medical image data, transferred from the terminal, to the image servers after converting a generalized protocol of the medical image data to the DICOM standard protocol.
The xe2x80x9cgeneralized protocolxe2x80x9d is http protocol, ftp protocol or the like used on Internet.
It is preferred that the image transfer system of the third aspect of the present invention be provided with a plurality of said protocol conversion servers.
Further it is preferred that the protocol conversion server be provided with a cache.
Further it is preferred that the protocol conversion server converts the format of the medical image data to a predetermined format and transfers the converted medical image data to the terminal.
The expression xe2x80x9cconverts the format of the medical image data to a predetermined formatxe2x80x9d means, for instance, to, when the medical image data is in a format which cannot be displayed by the terminal, convert the format of the medical image data to a format which can be displayed by the terminal, to, when the medical image data is too large in data size, compress the data size of the medical image data, and to convert the medical image data to a HTML document so that the medical image and the diagnosis information and the like can be displayed simultaneously by the terminal.
The image transfer system of the first aspect of the present invention is characterized in that a relay server which makes access to one of the image servers on the basis of instruction from the terminal to execute transfer of the medical image data on a DICOM standard communication system is connected between the terminal and the image servers. The relay server sends request for transfer of desired medical image data to one of the image servers according to instruction from the terminal and when the desired medical image data is not in the image server the relay server sends the request to another image server. Then the relay server receives the desired medical image data from one of the image servers and transfers the desired medical image data to the terminal. Accordingly, the terminal need not send the request designating an image server but can receive a desired medical image data by simply sending the request to a designated relay server, whereby the terminal can efficiently executes transfer of medical image data.
Further by providing the image transfer system with a plurality of such relay servers, when a plurality of requests are sent to a relay server from a plurality of terminals at one time, the relay server can distribute the requests to other relay servers, whereby transfer of medical image data can be executed at a high efficiency. Further even if one of the relay servers fails, the other relay servers can act for the fault relay server.
By providing the relay server with a cache for accumulating therein a plurality of pieces of medical image data, the relay server can store medical image data, once transferred to a terminal, in the cache and can transfer the medical image data to another terminal immediately after receipt of request from the terminal, whereby transfer of medical image data can be executed at a higher efficiency.
The image transfer system of the second aspect of the present invention is characterized in that the image transfer system is provided with a relay server which intervenes between the terminal and the image servers, receives transfer of medical image data prior to instruction from the terminal, and is provided with a cache for accumulating therein a plurality of pieces of medical image data. With this arrangement, the relay server can transfer a desired medical image data immediately after receipt of request from the terminal, whereby transfer of medical image data can be executed at a higher efficiency.
The image transfer system of the third aspect of the present invention is characterized in that the image transfer system is provided between the terminal and the image servers with a protocol conversion server which converts the DICOM standard protocol to a generalized protocol such as http, ftp and the like. With this arrangement, the medical image data on the DICOM standard protocol transferred to the protocol conversion server from the image server is converted to medical image data on a generalized protocol by the protocol conversion server and is transferred to the terminal. Accordingly, the terminal can display the medical image data by inexpensive web browser which supports the generalized protocol. The medical image data on the generalized protocol transferred to the protocol conversion server from the terminal is converted to medical image data on the DICOM standard protocol by the protocol conversion server and is transferred to the image server. Accordingly, medical image data can be observed through an inexpensive system such as a general-purpose personal computer at the terminal and medical image data can be transferred through Internet, whereby an exclusive network is unnecessary and the system can be formed at low cost.
Further by providing the image transfer system with a plurality of such protocol conversion servers, when a plurality of requests are sent to a protocol conversion server from a plurality of terminals at one time, the protocol conversion server can distribute the requests to other protocol conversion servers, whereby transfer of medical image data can be executed at a high efficiency. Further even if one of the protocol conversion servers fails, the other protocol conversion servers can act for the fault protocol conversion server.
By providing the protocol conversion server with a cache for accumulating therein a plurality of pieces of medical image data, the protocol conversion server can store medical image data, once transferred to a terminal, in the cache and can transfer the medical image data to another terminal immediately after receipt of request from the terminal, whereby transfer of medical image data can be executed at a higher efficiency.
Further when the protocol conversion server is arranged to convert the format of the medical image data to a predetermined format, medical image data can be converted to medical image data in a desired format conforming to the terminal, whereby efficiency in diagnosis can be improved.